score = eval(input('请输入成绩分数：'))
if score >= 60:
    print("成绩已合格")

a = eval(input("请输入成绩分数"))
if a < 60:
    print("成绩不合格")
if 60 <= a < 80:
    print("成绩一般")
if 80 <= a <= 90:
    print("成绩良好")
if 90 < a <= 100:
    print("成绩优秀")

a = eval(input("请输入成绩分数"))
if 60 <= score:
    print("成绩已合格")
    if 90 <= a <= 100:
        print("成绩很好")
a = eval(input("请输入成绩分数"))
if a >= 60:
    print("成绩及格")
    if a >= 90:
        print("成绩很好")
    else:
        print("成绩一般")

a = eval(input("请输入成绩分数："))
if a >= 60:
    print("成绩及格")
    if a >= 90:
        print("成绩很好")
    else:
        print("成绩一般")
else:
    print("成绩不合格")
    if a < 30:
        print("成绩极差")
    else:
        print("成绩较差")

a = eval(input("请输入一个数字"))
if a >= 90:
    print("成绩优秀")
elif a >= 80:
    print("成绩良好")
elif a >= 70:
    print("成绩中等")
elif a >= 60:
    print("成绩很好")
else:
    print("成绩不及格")

    def is_triangle(a, b, c):
        return a + b > c and a + c > b and b + c > a
    print(is_triangle(3, 4, 5))
    print(is_triangle(5, 12, 13))

year = int(input('输入年份'))
if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0):
    print(year, "是闰年")
else:
    print(year, "不是闰年")


